1. meet DSM-IV criteria for schizophrenia or schizoaffective disorder, and have been stabilized on an antipsychotic medication for the past 3 months. Antipsychotics include olanzapine, clozapine, aripiprazole, ziprasidone, and first-generation antipsychotics (mid to high potency). Polypharmacy is allowed as long as both medications fit into the same grouping (HWGL or LWGL).